Physical and Mechanical Properties of Single Crystals of Co-Al-W Based Alloys with L12 Single-Phase and L12/fcc Two-Phase Microstructures
Physical and Mechanical Properties of Single Crystals of Co-Al-W Based Alloys with L12 Single-Phase and L12/fcc Two-Phase Microstructures
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DOI：
10.4028/www.scientific.net/msf.638-642.1342
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发表时间：
2010-01
期刊：
影响因子：
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通讯作者：
H. Inui;Takashi Oohashi;N. Okamoto;K. Kishida;Katsushi Tanaka
中科院分区：
文献类型：
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作者：
H. Inui;Takashi Oohashi;N. Okamoto;K. Kishida;Katsushi Tanaka
在液氦温度下，用共振超声光谱法测定了Co_3（Al，W）单晶和多晶的三个独立弹性常数，其值比Ni_3（Al，Ta）的大15~25%，但比以前的计算值小得多。由于Co 3（Al，W）的E111/E100和cij的大值，具有平行于{100}良好排列和平行于{100}良好刻面的立方L12沉淀物的两相显微组织预期在Co基合金中非常容易形成，如实验所证实的。[001]取向的L12/fcc双相单晶的屈服应力值在800°C以下随温度升高而适度降低，然后在800°C以上迅速降低，屈服应力没有任何异常。
The values of all the three independent single-crystal elastic constants and polycrystalline elastic constants of Co3(Al,W) experimentally determined by resonance ultrasound spectroscopy at liquid helium temperature are 15~25% larger than those of Ni3(Al,Ta) but are considerably smaller than those previously calculated. Because of the large value of E111/E100 and cij of Co3(Al,W), two-phase microstructures with cuboidal L12 precipitates well aligned parallel to and well faceted parallel to {100} are expected to form very easily in Co-base alloys, as confirmed indeed by experiment. Values of yield stress obtained for [001]-oriented L12/fcc two-phase single crystals moderately decrease with the increase in temperature up to 800°C and then decrease rapidly with temperature above 800°C without any anomaly in yield stress.